fix my utter failure to handle branches/conditionals correctly (on ARM)

3 files changed, 17 insertions, 1 deletions

diff --git a/lib/arm64/jump-patch.h b/lib/arm64/jump-patch.h
index aa818d3..cc94f90 100644
--- a/lib/arm64/jump-patch.h
+++ b/lib/arm64/jump-patch.h
@@ -1,7 +1,6 @@
 #pragma once
 #include "arm64/assemble.h"
 #define MAX_JUMP_PATCH_SIZE 12
-#define MAX_REWRITTEN_SIZE (7 * 2 * 4) /* also conservative */
 static inline int jump_patch_size(uintptr_t pc, uintptr_t dpc,
                                   UNUSED struct arch_dis_ctx arch,
                                   bool force) {
diff --git a/lib/arm64/misc.h b/lib/arm64/misc.h
index c7fa5c9..84bd638 100644
--- a/lib/arm64/misc.h
+++ b/lib/arm64/misc.h
@@ -4,4 +4,6 @@
 #define TARGET_JUMP_PATCH_HDR "arm64/jump-patch.h"
 #define TARGET_TRANSFORM_DIS_HEADER "arm64/transform-dis-arm64.inc.h"
 #define MIN_INSN_SIZE 4
+#define TD_MAX_REWRITTEN_SIZE (7 * 2 * 4) /* also conservative */
 struct arch_dis_ctx {};
+static inline void arch_dis_ctx_init(UNUSED struct arch_dis_ctx *ctx) {}
diff --git a/lib/arm64/transform-dis-arm64.inc.h b/lib/arm64/transform-dis-arm64.inc.h
index 682613a..af2d4c7 100644
--- a/lib/arm64/transform-dis-arm64.inc.h
+++ b/lib/arm64/transform-dis-arm64.inc.h
@@ -16,3 +16,18 @@ static NOINLINE UNUSED void transform_dis_pcrel(struct transform_dis_ctx *ctx,
     }
 }
 
+static NOINLINE UNUSED void transform_dis_branch(struct transform_dis_ctx *ctx,
+        uintptr_t dpc, int cc) {
+#ifdef TRANSFORM_DIS_VERBOSE
+    printf("transform_dis (%p): branch => %p\n", (void *) ctx->pc, (void *) dpc);
+#endif
+    if (dpc >= ctx->pc_patch_start && dpc < ctx->pc_patch_end) {
+        ctx->err = SUBSTITUTE_ERR_FUNC_BAD_INSN_AT_START;
+        return;
+    }
+    /* TODO */
+    (void) cc;
+}
+
+static void transform_dis_pre_dis(UNUSED struct transform_dis_ctx *ctx) {}
+static void transform_dis_post_dis(UNUSED struct transform_dis_ctx *ctx) {}